Focal application of low-dose-rate brachytherapy for prostate cancer: a pilot study

To evaluate the feasibility and to report the early outcomes of focal treatment of prostate cancer using low-dose-rate brachytherapy (LDR-PB).

Seventeen patients were screened with multi-parametric magnetic resonance imaging (mpMRI), 14 of whom proceeded to receive trans-perineal template mapping biopsy (TTMB). Focal LDR-PB was performed on five eligible patients using dual air kerma strength treatment plans based on planning target volumes derived from cancer locations and determined by TTMB. Patient follow-up includes prostate specific antigen (PSA) measurements, urinary and sexual function questionnaires, repeated imaging and TTMB at specific intervals post-treatment.

Feasibility of focal LDR-PB was shown and short-term outcomes are promising. While the detection rate of tumors, a majority of which were low grade GS 3 + 3, was found to be low on mpMRI (sensitivity of 37.5%), our results suggest the potential of mpMRI in detecting the presence of higher grade (GS ≥ 3 + 4), and bilateral disease indicating its usefulness as a screening tool for focal LDR-PB.

Low-dose-rate brachytherapy is a favorable ablation option for focal treatment of prostate cancer, requiring minimal modification to the standard (whole gland) LDR-PB treatment, and appears to have a more favorable side effect profile. Further investigation, in the form of a larger study, is needed to assess the methods used and the long-term outcomes of focal LDR-PB.

Journal of contemporary brachytherapy. 2017 Jun 13 [Epub]

S Sara Mahdavi, Ingrid T Spadinger, Septimiu E Salcudean, Piotr Kozlowski, Silvia D Chang, Tony Ng, Julio Lobo, Guy Nir, Hamid Moradi, Michael Peacock, W James Morris

Department of Radiation Oncology, Vancouver Centre, British Columbia Cancer Agency., Department of Medical Physics, Vancouver Centre, British Columbia Cancer Agency., Department of Electrical and Computer Engineering, University of British Columbia., Department of Urologic Sciences, University of British Columbia., Department of Radiology, University of British Columbia., Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.